Machine for making lock nuts



1951 c. D. TRIPP 2,536,110

MACHINE FOR MAKING LOCK NUTS Filed Dec. 16, 1944 v 10 Sheets-Sheet l INVENTOR. CHESTER .1). TRIPP Jan. 2, 1951 c. D. TRIPP 2,536,110

MACHINE FOR MAKING LOCK NUTS Filed Dec. 16, 1944 l0 Sheets-Sheet 2 o (I I if I E I I o I I I 34 I I #2 lid .2/2 74 III [I ;Z I I M5 o o 65 I 4 2,

INVENTOR.

HESTER 1).fR/PP Jan. 2, 1951 c. D. TRIPP 2,536,110

- MACHINE FOR MAKING LOCK NUTS Filed Dec. 16, 1944 v 10 Sheets-Sheet s INVENTOR.

CH ESTER'ID.TE FF BY W 9 1951 c. D. TRIPP 2,536,110

MACHINE FOR MAKING LOCK NUTS Filed Dec. 16, 1944 10 Sheets-Sheet 4 INVENTOR.

CHEsrE/e 3. 77% "PP Jan. 2, 1951 c. D. TRIPP 2,536,110

MACHINE FOR MAKING LOCK NUTS Filed Dec. 16, 1944 10 Sheets-Sheet 5 CHESTERD.T1EIPP BY a WL Jan. 2, 1951 c. D. TRIPP 2,536,110

7 MACHINE FOR MAKING LOCK NUTS Filed Dec. 16, 1944 10 Sheets-Sheet e CHESTER. D. 77? 17F Jan. 2, 1951 c. D. TRIPP 2,536,110

MACHINE FOR MAKING LOCK NUTS Filed Dec. 16, 1944 10 Sheets-Sheet '7 v INVENTOR. CHESTER. b. TIE rpp Jall- 1951 c. D. TRIPP 2,

MACHINE FOR MAKING LOCK NUTS Filed Dec. 16, 1944 10 Sheets-Sheet 8 u==a L7 LLJJ I I 6/ I m I Jan. 2, 1951 c. D. TRIPP 2,536,110

MACHINE FOR MAKING LOCK NUTS Filed Dec. 16, 1944 10 Sheets-Sheet 9 llilii" IN VEN TOR.

STEI T mp BY Jan. 2, 1951 c. D. TRIPP 2,536,110

MACHINE FOR MAKING LOCK NUTS Filed Dec. 16, 1944 10 Sheets-Sheet 10 IN V EN TOR.

E /E DJ'RJPP Patented Jan. 2, 1951 MACHINE FOR MAKING LOCK NUTS Chester D. Tripp, Chicago, 111., assignor to Grip Nut Company, South Whitley, Ind., a corporation of Illinois Application December 16, 1944, Serial No. 568,501

16 Claims.

The present invention relates to an improved method and machine for making lock nuts and more particularly to a machine for converting standard commercial nuts into lock nuts havin a predetermined locking or gripping force.

While the machine disclosed and claimed in my copending applicaton Serial No. 517,409, filed January 7, 1944, now Patent No. 2,408,457, issued October 1, 1946, provides a wholly satisfactory machine for converting standard commercial nuts into lock nuts, the machine in that application necessitates the reciprocation of a nut supporting table, nut feeding mechanism and other relatively heavy machine parts. Furthermore, it has been found that the predetermined characteristics of the machine of the above-mentioned application can be substantially improved by the provision of means for predetermining the initial pressing force exerted on the nut and allowing the pressing force to build up to a predetermined higher value as the press'ng of the nut continues. In this way extremely accurate control of the gripping characteristics is obtained, since the indenting force can never exceed the predetermined value notwithstanding inaccuracies which might be built into the machine.

It, accordingly, is a major object of this invention to provide a novel apparatus embodying certa-n improvements in the method of my Patent No. 2,352,668, issued July 4, 1944, and to provide other improvements and refinements in lock nut making apparatus, as will hereinafter appear.

Another important object of the invention is to provide a machine for making lock nuts, us'ng a fiuid pressure actuated indenting tool of rapidly increasing contact area, which embodies means for initially subject'ng a nut to a predetermined minimum indenting pressure, then progressively increasing the indenting pressure to a predetermined max'mum value, thereby wholly compensating for structural inaccuracies in the machine and making possible the production of effective lock nuts having substantially more uniform locking character'stics than formerly, irrespective of varations in the axial dimension and density of the nuts.

It is also an object of the invention to provide a nut deforming machine havng novel nut gripping means adapted to retain the nut in position while deforming it.

A further object of the invention resides in the provision of a lock nut making-or indenting machine having novel means for predetermining and limiting the efiective stroke of the indenting dies to assure uniform values of the locking characteristics in successive nuts, irrespective of the axial dimension and density of the nuts.

Still another object of the present invention is' to provide a lock nut making or indenting machine wLth a stationary nut supporting table and reciprocating indenting mechanism having a substantially constant length of stroke and means for controlling the efiective indenting movements of the indenting dies independently of the means for reciprocating the indenting mechanism.

The invention also has for one of its important objects to provide novel hydro-pneumatically actuated'mechanism for controlling the operation of the nut indenting dies.

A further object of the present invention resides in the provision of novel means for reciprocating the dies and pressure applyin assembly, togetherwith a. novel lubrication system therefor.

It is also a still further object of my invention to provide simply constructed and positively operating nut feeding and gripping means together with means for automatically discharging the finished lock nuts from the machine.

The present invention further comprehends I the provision of a simple and efficiently operating means for automatically controlling the operation of nut gr'pping and nut discharging mechanisms in timed relation to the reciprocating movements of the nut indenting die assembly.

With the foregoing and other subordinate obiects in v'ew, the present invention comprises the improved machine for making lock nuts, and the construction and relative arrangementof its several parts, as will be hereinafter more fully described, illustrated in the accompanying drawings and subsequently incorporated in the subjoined claims.

In the drawings wherein similar reference char"- acters designate corresponding parts throughout the several views:

Figure 1 is a front elevational view of a machine illustrating one practical embodiment of the present invention, certain of the parts being omitted to more clearly disclose the novel features thereof;

Figure 2 is an elevational view of the right hand side of the machine;

Figure 3 is a rear elevation of the machine, certain parts being omitted in the interest of greater clarity;

Figure 4 is a vertical sectional view taken sub: stantially on the line 44 of Figure 1;

Figure 5 is a similar sectional view taken substantially on the line 5--5 of Figure 1;

- Figure 6 is a horizontal sectional view taken substantially on the line 6-6 of Figure 5;

Figure '7 is a detailed sectional view of one of the die actuating units;

Figure 8 is a detailed elevation partially in section, illustrating the lubricating system for the die reciprocating mechanism;

Figure 9 is a detailed sectional view of the lubricant distributing pump;

Figure 10 is a detailed elevation of the suction delivery oil tank;

Figure 11 is a top plan view of thenut feed conveyor with certain parts shown in sectionto illustrate the step by step conveyor actuating mechanism; I I

Figure 12 is a fragmentary viewshowingthe pawl and ratchet conveyor actuating mechanism illustrated in Figure 11;

.Figure 13 is a sectional view taken substantially on the line 'i'3|3 of Figure 11;

Figureli schematic elevatlon'with parts ,shownfin section to illustrate the nut gripping .irriecha'nism and fluid supply pipe connections fonoperatingthe movable nut gripping elements; I :Figure15 is a .fragmentaryplan.view.illus- '-'trating the manner in which the gripping elen'rients grip the nuts during the indenting operiation of Ithe..machine Qliig'ure I6 is .a sectional view of the valve mechanism illustrated in Figure 14;

. Figure 16A is a vertical sectional view 'taken substantially on the line a.a of Figure 16; fFifgure 17 is a schematic view with certain "parts shown in section, illustrating the air supply .valve for the nut discharging means together with the operating means therefor;

I ..Figure.18.-is.an enlarged sectional view of the air. inlet pressure. regulator;

Figure '19 is an enlarged sectional View. of the outletwliquid pressure regulator through which the 'lliquid is. returned from the die operating piston cylin'ders tothe tank or reservoir;

; lFigurexzo is an:enlarged elevational view .of

"the liquidlevel-indicator and equalizing-means; v Fiigure..21 is .a'detailed elevation of vthe drive sIlialftQforoperating the'piston and cylinderassemblies; -'.Fig.ure 22 is a transverse section taken substantially on the line 2222 of Figure 21. II

"Figure2 3 is a detailed elevation of a preferred form of .nut indenting die; I

';Figu1'e'24 is a bottom plan view of the die shown in Figure 23;

Figure 25 is a plan view of one form of nut 'after ithas'been deformed by the die shown in Figure 23; and

Figur'e 26 is a sectional view of'the deformed nut taken substantially on the line 26i!5 of Figure 25.

"Referring in further detail to the drawings, in'the embodiment of the invention which I have selected for purposes of illustration, the supporting superstructure for the several mechaf'ni'sms to be presently described in ldetail is suitably mounted upon the bed plate 38, having its'opposite ends fixed upon the upper ends-of the floor pedestals or standards 31. As herein shown this superstructure includes the vertical r sidemembers 32 connected attheir upper ends 'bythe cross bar 33, the opposite ends of' which are connected with the forward end ofthebecl plate 30 by the diagonal brace rods 34, I I

'Between thespaced. side members 32 of the 4 machine frame the die operating piston and cylinder assemblies are mounted for vertical reciprocation. As herein shown, and seen more clearly in Figure '7 of the drawings, each of these assemblies includes upper and lower heads 35 and 36 respectively, between which the ends of the cylinder 31 are rigidly clamped in fluid tight connection bymeans of ;a plurality of .tie rods 38. LYIhe ,lowertepiston heads S36 at .the front and rear sides thereof are rigidly connected by the aperztured plates 39 which have vertical sliding movementupon front and rear rods 49 suitably fixed "attheir-lower ends in the plate 4| mounted upon the central por tion of the bed of the machine.

The upper cylinder heads are also connected by .the hollow cross bar 52, formed in the upperposition thereof with a longitudinally extending lubricant receiving channel 3. At its oppositefends transverse bearing members 44 are fixed to the bar 42 and a similar bearing mem- :,ber Ahis centrally. fixed thereto. In these bear- .At. each side I of the bearing member 85, 'a roller .wis'eIsuitablyIfixed in the .hub of a. large g'ear wheel .54. .At the opposite side of the machine 'frarnethe other end of the, jdriveshafthlljterininateslini the flangenor. disk of .enlargedjdiameter, for. a, purpose which'will-be presently explained.v I II 'At each side. of its central .portion 49; the drive "shaft is formed with an eccentric portion I56 which,. respectively; have .peripheralbearing conltactupon thespaced rollers 741 onthe rod 45.

Between these eccentric .p ortions "5 6 of the shaft and .the bearing supported .Ip'arts"5l thereof, the

"'sha ftfis formed with thegcylindrical DQrtionsjE'l,

concentric with the shaft axisnand ,of slightly greater 'diameterthan the partsil.

With each -of the shaftportions 5l,..the;upper aridilower. sections of .a yok'efillus'trated-infFigure .4. are engaged at the. .buter sides of the adjacentl e ccentric portion 56 .of \the shaft. 'Each lower.yoke section v58 has-a. depending partjil which is fixed to'therod-efi "and at itsupper .end is formed with forwardiy and .rearwardly projecting .apertured ears 60in which the .lower endsfof vertical.rods-6| are suitably fixed. fllhe upper yoke section 62 has similar apertured ears 63 through which the rods 6 I -;loosely= extend: and springs 64 onsaid rods act to. normally-yieldingly urge the .two yoke sections toward each-other and hold the same yieldinglyyin. contaetwith the peripheral surface 1 of one of the shaft sec- ..tionsaEl. I I I I Ally- 9 71 1 331 an tbe i m y iq transmitting power through the gearj lzrto'rthe shaft 50, but-as herein shown, for thisgpurp ose, I provide the .countershaft fifi mountedin suit- ;able bearings 66 .011 the rear vertical ved esnf .the frame; members 32. 1A. belt wheel :Blisiiiiied to one end of said shaft and connected by drive belt 68 with the shaft of the motor 69 shown in Figure 1. To the other end of the shaft 65, a spur gear of relatively small diameter is affixed and is in constant mesh with the teeth of the large gear wheel 54. Thus it will be understood that shaft 50 is driven at a comparatively low speed. 4

A reciprocatory piston H in each of the cylinders 31 is fixed to the upper end of a piston rod 12 movable through the stuffing box 13 on the lower cylinder head 36. A die holding head 14 is detachably carried by the lower end of the rod 12 and has a threaded bore 15 to receive the threaded stud or shank 11 of the die member 16. As shown in Figures 23 and 24 of the drawings, this indenting member has a flange 18 for abutting contact with the end face of the head 14 and from which the indenting stud 19 axially projects. The end face of this stud is formed with three shallow indenting teeth, the crests 80 of which are spaced apart for substantially 120. The effective operation of this indenting die upon the nut to provide the latter with locking characteristics will be subsequent- I 1y explained.

Upon the rear edges of frame members 32 and above the shaft 65, a transversely positioned tank 8| is secured at its opposite ends by any suitable means, such as the metal straps 82. A predetermined quantity of water, oil or other liquid is supplied to this tank from a pump or other convenient source.

To the bottom of the tank 8|, at the approximate center thereof,- the upper end of a pipe 83 is connected and the lower end of this pipe is connected by coupling means 84 with the branch pipes 85. These pipes are connected by suitable coupling means with one end of the flexible pipes 86, the other ends of which are connected with pipe nipples 81 threaded into the outer ends of the passages 88 in the upper cylinder heads 35 through which the liquid is supplied from the tank 8| to the respective piston cylinders 51. The connection between the pipes 85 and 86 includes a conventional ball check valve, indicated at 89, to prevent back flow of the liquid through the pipes 85, and the T coupling members 90 which are connected with the return inlet ports 9| of the return flow pres-- sure regulating valves, indicated generally at 92, and shown in detail in Figure 19 of the drawings. Referring thereto, the valve piston 93 is normally urged downwardly by spring 94 to close the connection between the inlet port 9| and the outlet port 95. The pressure force necessary to lift the valves 93 and open the connections between the inlet ports 9| and outlet ports 95 may be regulated and predetermined by the adjustment of the rod or stem 96 with relation to the spring 94. The lower ends of the outlet ports 95 are connected by the pipe lines 91 with the pipe 98 connected with one end of the tank 8| As shown in Figure 7 of the drawing, the low-- er cylinder heads 36 are also provided with outlet passages 99 for liquid leaking past the pistons 1| with which pipes I00 are connected to return such liquid to the pump cylinder or other source of supply for the tank 8|.

Upon the frame members 32 and above the tank 8|, a small diameter moisture separating tank IN is secured by means of the clamps I02 to one end of which air is supplied through the pipe line I03. At the other end of said tank,

the outlet I04 is connected by the coupling I05 with the air inlet pipe I06 of the pressure regulator I01 shown in detail in Figure 18 of the drawings. Preferably the coupling I05 is of T form for the connection therewith of the pipe I08 through which air may be supplied to other apparatus in the plant. The outlet side of the pressure regulator I01 is connected by pipe I09 with the pressure gauge 0 coupled with the pipe III connected to the top of the tank 8| as most clearly shown in Figures 3 and 5 of the drawings. A valved drain pipe H2 is connected to tile bottom of the tank I0| as seen in Figure While any preferred type of ressure regulating valve I01 may be employed, as herein shown this valve includes a diaphragm 3 having its marginal portion secured between the upper and lower sections 4 and H5 respectively, of the valve casing. The lower section I I5 has an axial bore I|6 provided with a section II1 of reduced diameter with which the pipe I86 communicates. A valve member I I8 normally closes communication between the bore H6 and the chamber II9 of large diameter at the lower side of diaphragm II3. This chamber is connected with the outlet pipe I09 by the port I20. A light coil spring IZI bearing at its outer end against the closure plug I22 yieldingly urges the valve member III? to closed position with the upper end of said valve member in contact with the lower face of the diaphragm II3. Upward movement of the diaphragm is yieldingly resisted by coil spring I23, such resistance being regulated by adjusting screw I24 threaded in the casing section 4 and locked in adjusted position by a nut I25.

As thus far described, the operation of the machine is as follows: With the pistons 1| in their lower positions a predetermined volume of liquid is supplied to the tank 8| to completely fill the cylinders 31 above the pistons and the connections between the same and the tank 8| until. said tank is substantially about one-half filled with the liquid. Air is admitted to the tank above the level of the liquid through the valve I01 to establish a predetermined pressure as shown by the gauge H0. The valve H8 is then closed and the spring I23 properly adjusted until the pressure on the upper side of diaphragm |I3 substantially balances back pressure in chamber |I9 from the tank 8|.

Assuming that two standard nuts have been positioned upon the upper surface of plate 4| in axial alignment with the respective indenting dies 16, in the rotation of drive shaft 50, the cylinders 31 and pistons 3| are moved downwardly as a unit by the thrust of the eccentric shaft portions 56 against the rollers 41, the lower yoke sections 58 being thrust downwardly relative to shaft sections 51 against the resistance of the springs 64. When the crests of the lugs 19 of the die members contact the upper surfaces of the respective nuts at the edge of the bore therein, the pistons 1| are forced upwardly in the cylinders 31 against the resistance of the liquid and the air pressure thereon within the tank 8|, resulting in a progressively increasing pressure of the respective die members upon the nuts. If the nuts happen to be of difierent axial lengths, the dies will of course contact the respective nuts at different times. Nevertheless the length of stroke of the pistons 1| will'be the same. However, since the indenting pressure is derived solely from the hydro-pneumatically operated piston the respective feed belts as they approach the nut gripping means presently to be described.

Upon the rear end of the plate M and in line with the respective feed belts, stop plates 262 are adjustably mounted. Each of these plates has a longitudinal slot 263 which receives the spaced clamping bolts 264 threaded to plate M and whereby said stop plates may be secured in fixed position with their forward end edges disposed in predetermined relation to the path of movement of transversely movable nut gripping members, in accordance with the size of the nut to be indented.

Any suitable means may be provided for imparting a step by step feeding movement to-the belts I56. As herein shown a crank arm I62 is journalled by a suitable antifriction bearing I63 on one end of the shaft I54 and carries the spring pressed pawl I64 engaging the teeth of the ratchet I65 keyed or otherwise suitably fixed to said shaft, as clearly shown in Figures 11 and 12 of the drawings. As seen in Figure 2, the other end of the arm I62 is pivotally connected with the lower end of the pitman rod I66, the upper end of which is pivoted as at I61 to the outer side of the flange or disk on the end of the drive shaft 58 adjacent to the periphery of said disk. This connection is so located with respect to the shaft eccentrics 56 that in the upward movement of the dies, the arm I62 is moved in a clockwise direction, whereby the pawl I64, coacting the ratchet I will rotate shaft I54 and move the nut feeding belts one step so that the rear or innermost nuts on said belts will be moved into abutting contact with the forward ends 262 of the stop plates 262 and in position to be engaged by the gripping means which will now be described.

Between the guide rods or posts 48 and at each side of a longitudinal vertical plane intersecting the axes thereof a nut gripping member I 68 is rigidly fixed to the surface of the plate M by means of bolts or screws I69. These members are arranged in transverse alignment, and the outer ends thereof are provided with the notches I18 to receive one side of the nuts. particularly in Figure 14 of the drawings, in transverse alignment with the members I 68 movable gripping members I1I are fixed to the inner ends of the piston rods I12 connected with pistons I13 in cylinders I14 which are suitably fixed to bracket members I15 bolted or otherwise secured to the opposite side edges of plate 4|. The springs I16 in the cy inders I14 yieldingly resist inward movement of the pistons I13 and normally retain the gripping members I1I in outwardly s ggced relation from the fixed gripping members Operation of the pistons I13 to move the members I1I inwardly to grip the nut between said members and the members I68 is properly controlled in timed relation to the movements of the nut feeding belts and the vertical reciprocation of the indenting dies by means of the valve mechanism il ustrated in detail in Figures 16 and 16A of the drawings. As shown in Figures 5 and 14 the valve casing I 11 is suitably mounted on a fixed part I18 01 the machine frame. This valve casing is of general rectangular form and has a chamber I19 which receives air through the pipe line I19 connected with the coupling between pipes I89 and II I. A valve member I in the chamber I19 has sliding contact with the side wall of said chamber opposite to the air inlet connection and is fixed to the upper end of a rod I8I which is movable through a suitable stuff-.-

As shown more 10 ing box I82 on the lower end wall of the valve casing. This rod is loosely engaged through an opening in the arm I83 fixed to the rear guide plate 39 connecting the lower cylinder heads 36 (Figure 4). A spring I84 on the rod I8I bears upwardly against the arm I83 and against the nut I85 threaded on the lower end of the rod and yieldingly urges the stop nut I86 on the rod I8I into contact with the upper side of the arm I83. Thus the spring I84 will yieldingly limit or cushion the downward movement of the valve I88 in the downward operating stroke of the die and piston assemblies As shown in Figure 16--A, the side of the valve member I88 having contact with the wall of the chamber I19 is provided with a recess or cavity I81 which, in one position of said valve, is adapted to connect the exhaust port I88 in the side wall with a port I89 extending upwardly through the top of the valve casing and with which the coupling head I 99 is connected. This head is formed with an air receiving chamber I9! and outlet passages I92 leading therefrom to the pipe lines I93 coupled to the head I98 by suitable connections I94. The other ends of the pipe lines are respectively coupled by connections I95 with the outer ends of the respective piston cylinders I14.

Direct communication between the ports or passages I92 and the chamber I 9I is normally c'osed by means of the ball valves I96 urged to their closed positions by means of the coil spring l91 positioned between said valves. However, chamber I9I is connected by relatively small diameter metering by-passes I98 with each of the pipe lines I93. 1

From the above description, it will be understood that air is supplied to the valve through the connection I19 and as the piston and die-assembly moves downwardly, port I89 is uncovered by the valve I89 so that airv islay-passed from the chamber I19 through the metering ports I98 around the valves I96 to their respective cylinders I14. The nuts having been fed by the belts I56 to position in alignment with the fixed gripping members I 68, as above explained, the pietons I13 are thus actuated to move gripping members I1I inwardly against the action of the springs I16 to securely grip and hold the nuts between said members HI and the opposing members I68 so that they are retained in accurate coaxial relation with the descending die members 16 during the indenting operation. In the ensuing upward movement of the dies and piston and cylinder assembli s, valve member I86 is moved over the port I89, thus connecting said .port through the chamber or recess I81 with the. exhaust port I88, The cylinders I14 will then be exhausted in the outward movement of pistons I13 under the action of the springs I16, the air passing therefrom through the passages I92 of relatively large diam? eter and unseating the valves I96 thus providing for. a comparatively rapid unrestricted flow of the air from the chamber I9I through port I89 and recess I81 to the exhaust port I88.

I have also provided a simple and effective means for automatically discharging the finished indented nuts from the machine as shown more particularly in Figures 5, 6 and 1'1 of the drawings to which reference should now be had. At the rear side of the drive shaft 58 the valve housing I99 is suitably mounted upon a fixed part of the machine frame and is formed with an air inlet chamber 288 and an air outlet chamber 28I Communication between these chambers is normally' closed by the valve 293 resiliently urged to seat by the spring zttjbearm'g at ne brits endsagainst one side of" the valve housing [99 and at its other end'a'gainst the collar 2B5 fixed to the; outer end of the valve stem 206.

' The inletchamber 209' is connected by the" pipe line] 01 with the air inlet pipe [06 and the outlet chamber 20! ofthe'valve' housing is connected by the pipe line 208 with a horizontal passage or borej 2p}; in the plate 41 which opens upwardly through the top surface thereof. The outlet end f this passage is connected with a coupling member 210 threaded into the plate 4| andh'a'ving angularly disposed branch outlets 2| overlyir'i'gthe upper surface of said plate. With each of these outlets a pipe or tube ZIZ is connected and extends rearwardly' therefrom, said pipes or tubes being disposed at relatively opposite sides of the front guide rod or post 4U'fo'r the die and piston assembly.

:the end of, an arm 2'5 on the Valve housing I99 seepa e-gee with the outer end of the valve em.. B5- t i ith nn f 's pq th t n illerd e Z13 s es e. P x en le 1 14 h rave- 21 s'iqr d- 9 gr ate -i n a a n the .si p rin %.thi 'sfid ifiitins a r m th chamber 200 to the outlet chamberzili of the valvehousing, from which it passes througlithe ii eline 98 am; passa ifli t0 e i ti c upu ezw and, ip 0 1 t es, 2'2 i flf rea en f these u e re l d,elose aaiae i to 1 ute end fi ths fi nut r pp ,me i hers jfifisg thatafter the nuts have been in dentsd and el a ed by. t m va le grippin members 11!, air blasts will be directed by the 212 against the nuts toeject olr discharge 2 7 s mere rwa dl nt i d charg c u es I W ether mqvei o rdly, b g av ty n e deposited in suitable, collection receptables at the .rsarsid nfthe ma n I-Iaving now described the several novel istruc .tural features of the invention, the functional operation of the machine will be understood as ws: .1. i

In tlie rotation of the drive shaft 50, the ;upward. movement of the piston and jeylind'er assembliesanddies16, the nut feeding belts I55 are t e ted aph said. b l s f edi siii'l nut into position inr tra nsversei alignment with the nx d memper 1'68, In 'th'e downward 'in'b'vt oftherpiston anddie assemblies, prior to Heft he diesj with t nuts, valve lflfl is ac ated init ema r a oveex lai d. to mi h shme siir itothe l e s '14" an move the gripping members If inwardh to ,transver elr spl ce t einuisif m t e respeconveyors thus securelyclamping and holding the nuts between said grippin iiieriibrjs m and itheiixed gripping members I58 in accurate coaxial alignment with the respective die mem b'ers 7e. Afterjthe die meters have engaged and indented the in the manner st ve ex: 1

plained; in the renew ng upward movement of t e die and piston "assemblies yaiv'e' use m'b'ves upwardly its release the air pressure grain at racers In so that megripping;meii1 ers;'|1| sie 0 11in Figureszand 6 of the drawings in 'l etenir2'l3'jnowengages the lever m and 'mdvs assemblies under the action of the eccentric por tions 56 of the drive shaft, after the indenting members 16 contact the respective nuts, in the continued downward relative movement of the piston cylinders 31 the hydropneumatic' means above described supplies a progressively increasing pressure to the pistons H. The maximum pressure applied by the die members to the nuts may be' accurately controlled and predetermined by'proper adjustment of the pressure regulating vane I67 and the back pressure control valve 93. This maximum indenting pressure will be substantially the same, regardless of differences in the" axial length or minor differences in density of the respectiwenuts so that the distorted thread portions [28 of the nut will have substantially identical locking characteristics. In Figures and 26 I have shown a nut provided with three indentations. However, it will be apparent that if desired the indenting members 15 may be formed with any desired number of the indenting teeth so that a greater or less number of distorted thread sections may be formed at the end of the nut bore. The means which I provide for locating and securely holding or gripping the nuts together with the mechanical means for operating and guiding the unitary movement of the piston and cylinder and die assemblies under theaction of the eccentrics 56 insures an accurately centered contact of the dies with the respective nuts. Since. thereafter. indenting pressure is applied to the dies solely by pressure fluid and independently of the mechanical operating means for the piston and die assemblies, the aceurate formation of the indentations in the nut face to the desired depth with precisely the same thread distortion I28 at each indentation is obtained regardless of physical variation's in different nuts or structural inaccuracies in the inachine Therefore, the locking action or pre sure upon the threads of the complementary bolt or other member with which the nut is engaged will be substantially identical at each of the spaced points around the periphery thereof.

7 By such precise control of the initial and final indenting pressures the extent to which the helix angle of the spaced portions of the conventional nut threadis di placed or altered is definitely and accurately limited regardless of variation in axial length of the nuts. Thus the nut is pro vid'ed with efiiciently functioning self-locking 'characteristics, while it is also capable of repeated re-use without such mutilation of the bolt threads as would preclude the application of a standard nut to the same bolt.

7 It will also be appreciated that my present invention provides means for feeding the nuts to the machine and discharging the finished nuts therefrom which is operatiyely controlled by'the driveshaft 50 in accurately timed relation with the vertical reciprocating motion of the piston and die assemblies, The nut feeding conveyors above described having the h nged metal plates 1594s pportingthe nuts provide smooth surfaces forfs idingeontaet'with the nuts after movement of the nuts is arrested by "the stops I62. When these conveyor plates be'c'onieundui 'worn, they can be readily removed from the conveyor belt and new plates substituted therefor at nominal expense. It will be further noted that the machine organization as a whole comprises a minimum number of parts of comparatively simple structural form, mounted and arranged in a compact assembly upon a machine frame which will occupy a minimum of floor space.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is:

1. In a machine for converting standard nuts into lock nuts having uniform locking characteristics, a nut supporting member and a nut indenting die, a piston rigidly connected with one of said parts, a cylinder for said piston, means for supplying a fluid pressure medium to said .cylinder, a driven shaft having an eccentric portion, a roller mounted on said cvlinder, and vie dable yoke means connected with said cylinder loosely embracing the driven shaft to retain said roller in peripheral contact with the eccentric portion of said shaft and impart unitary reciprocation to said piston and cy inder.

2. The machine defined in claim 1, together with means connected with the cylinder and p ston assembly and actuated in the reciprocation thereof to supply lubricant to said roller and eccentric.

3. In a machine for converting standard nuts into lock nuts having uniform locking characteristics, a device for releasably holding a nut, a cylinder and piston, power driven mechanism for reciprocating said cylinder and piston as a unit in coaxial relation with the nut, an indenting die carried by the piston and movable into contact with the nut in the unitary movement of the cylinder and piston in one direction, means for thereafter applying a progressively increasing resistance to movement of the piston with the cylinder in said direction to produce an effective indenting pressure of the die upon the nut. and mechanism automatically actuated in the unitary reciprocation of sa d cylinder and piston for controlling the operation of said nut holding device to nut holding and releasing position.

4. The machine defined in claim 3 together with additional means operatively cont olled by said power driven mechanism for discharging the indented nuts from the machine.

5. The machine defined in c aim 3, in which said nut holding device includes relatively movable parts, and said automatically operated mechanism comprises a fluid pressure operated motor connected with one of said parts, and means connected with and actuated by the cylinder and 7 14 a coaxial relation with the nut, means for feedin nuts to said holding means, an indenting die carried by the piston and movable into contact with the nut in the unitary movement of the cylinder and piston in one direction, means for thereafter applying a progressively increasing resistance to movement of the piston with the cylinder in said direction to produce an effective indenting pressure by the die upon the nut, and actuating means for said nut feeding means operatively connected with said power driven shaft and actuated thereby to feed a nut to said holding means.

7. The machine defined in claim 6, in which said nut holding means includes relatively movable parts, together with means connected with and actuated by the cylinder and piston assembly to control the operation of saidnut holding means to nut hoding and releasing positions in timed relation with the actuation of said feeding means and the'reciprocating movement of said cylinder and piston assembly.

piston assembly, an indenting die carried by the piston, power driven means operatively connected with said cylinder and piston assembly to reciprocate the same as a unit and contact the die with tl e nut, and hydro-pneumatic means for thereafter transmitting nut indenting pressure to the die through said piston, said means including a container for hydraulic medium connected with said cylinder, means for maintaining a predetermined air pressure within said container to estab-- lish an initial pressure of the hydraulic medium upon said piston, and means for variably regulating back pressure of the hydraulic medium through said cylinder connection to produce a predetermined progressivey increasing nut indenting pressure of the hydraulic medium upon the piston after contact of the die with the nut in the movement of the cylinder relative to said piston.

9. In a nut indenting machine, a pair of cylinders and a piston in each cylinder having a rod, a nut indenting die carried by each piston rod, means for positioning and holding nuts to be en aged by the respective dies, connecting means between the piston rods to prevent relative angular movement thereof while permitting of their relative axial movement in accurately centered relation to the respective nuts, power driven means for reciprocating the cylinder and piston assemblies as a unit to contact the indenting dies with the respective nuts, and means for thereafter applying a progressively increasing F resistance to relative movement between the pistons and the respective cylinders, to produce an efiective indenting pressure by the dies upon the respective nuts.

10. The machine defined in claim 9, together with means for equalizing the pressure increase within said cylinders upon the respective pistons.

11. Nut feeding and positioning means for nut indenting machines comprising an endless nut conveyor, means adjacent one end of the conveyor to position a nut for engagement by an indenting die, including a nut gripping member movable transversely across the conveyor, operating means for the conveyor, and means for actuating said gripping member in timed relation with the conveyor operating means to engage a nut thereon and transversely displace the same from the conveyor for effective engagement by said nut positioning means.

' 12. The nut feeding and positioning means defined in claim 11, wherein an adjustable stop t i Q 15 above the conveyor arrests movement of the nut with the conveyor to dispose the nut in alignment with said movable gripping member.

13, The nut feeding and positioning means defined in claim 11 wherein said conveyor includes a plurality of metal nut supporting plates in longitudinal succession and a stop member arrests movement of the nut with the conveyor plate and positions the same in alignment with said movable gripping member.

l4. A machine for making lock nuts of uniform gripping and locking force from nuts of varying heights and density formed by quantity production methods, comprising a pair of members mounted for relative movement toward each other and operable to press a nut therebetween, one of said members being adapted to support a nut and the other comprising indenting means operable toindent a face of a supported nut and modify a portion of the nut threads in proportion to the depth and area of indentation, means for positioning a nut with respect to said indenting means, holding said nut during the indenting operation, and automatically releasing the indented nut upon separation of said indenting means and the nut, driving means for imparting a reciprocating movement to one of said members to bring said indenting means into pressing re1ationship with a supported nut, and pressure means having a predetermined minimum pres- 1 sure and a predetermined maximum pressure and operable to independently control further relative movement between the indenting means and nut. whereby successive nuts will be subjected to identical pressing forces irrespective of variation 16 in physical structure of differentnuts or mechan ical inaccuracies in the machine.

15. The combination defined in claim 14 together with air blast producing means operated in timed relation to said driving means for eject ing the completed nuts and moving them to a point of discharge.

16. The combination defined in claim 14 wherein said pressure means comprises a cylinder carried by one of said members, a piston operable in said cylinder and arranged to engage said nut indenting means with a nut, an inlet pressure line adapted to maintain predetermined minimum pressure in said cylinder between said piston and an end of said cylinder, and an outlet pressure valve connected to said line adapted to predetermine the maximum pressure attained on relative movement of said cylinder and said piston,

CHESTER D. TRIPP.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 12,000,056 Wilson May 7, 1935 2,249,149 MacMillin July 15, 1941 2,266,933 Williams Dec. 23, 1941 2,352,668 Tripp July 4, 1944 2,385,390 Tripp Sept. 25, 1945 2,408,457 Tripp Oct. 1, 1946 2,438,951 Stephens Apr. 6, 1948 Certificate of Correction Patent No. 2,536,110 January 2, 1951 CHESTER D. TRIPP It is herebycertified that error appears in the printed specification of the above numbered patent requiring correction as follows:

Column 1, line 46, for varations read variations; column 4:, line 17, for the Word position read portion; column 8, line 29, for has is read has its;

and that the said Letters Patent should be read as corrected above, so that the same may conform to the record of the case in the Patent Oflice.

Signed and sealed this 5th day of June, A. D. 1951.

[sun] THOMAS F. MURPHY,

Assistant Gammtssz'oner of Patents. 

